As the 1967 franchise review drew near, Rediffusion Television (originally Associated Rediffusion, until the company changed its name at the start of the previous franchise period after the departure of Associated Newspapers as an investor) was no doubt feeling fairly secure. For a dozen years since ITV's opening night, the company had provided London, Monday to Friday, with what it firmly believed was 'the best of all television', as the signage on the front of its building read. Rediffusion's - or rather its parent company's - deep pockets had kept ITV afloat in the early, dark days, and had secretly bailed out Granada; it had produced good, solid programming. The company was thus confident as it went through the ITA interviews prior to the allocation of the next round of franchises - perhaps too confident; even, according to some commentators, a little arrogant.

Meanwhile, further north, ABC under Howard Thomas had successfully managed the midlands and north weekend franchise since 1956. ABC had only once been criticised by the ITA - for weak presentation - and the company had addressed that swiftly. The ITA was pleased with its performance.

But changes were afoot in the layout of the regions. The old 'pan-North' 'Granadaland' was to be split in two. Outside London, the old weekday/weekend splits were to be abolished. Thus ABC's home territory was to disappear.

The ITA wanted to give ABC what both organisations believed was appropriate, namely the London weekend contract, which they would probably have run under the name 'Capital Television'. Rediffusion would have held London weekdays - a mild reproof. But David Frost's consortium had put in an extraordinarily convincing bid for the weekends in the capital, with impressive backing and personnel. The ITA had to show that it was fair and that it would give new blood as good a chance as old. London Weekend Television, as it was soon to be known, could not be turned down.

But ABC, too, was a weekend company. Although the original 'big four' franchises had been designed to be roughly similar in size (on the basis of weekly broadcasting hours times area population served), there was a big difference between running two days a week, albeit in two regions, and the most prestigious franchise of them all, London weekdays. They simply did not have the resources. Rediffusion, on the other hand, had the manpower, the facilities, and the experience. But Lord Hill liked ABC, while towards Rediffusion the Authority was, at the least, indifferent.

The solution the ITA came up with was a shotgun marriage between ABC and Rediffusion; more accurately, a new company was to be formed by the two parent companies, Associated British Pictures Corporation and British Electric Traction, to run London weekdays. ABC was to have 51% and Rediffusion 49% of the new company. This gave ABC, and Howard Thomas, the pick of the experienced professionals at Rediffusion, but the style was unmistakeably to be that of ABC. Even its introductory start-up music, 'Perpetuum Mobile', followed ABC south. Thames Television was the name chosen for the new company - curiously enough one that had been discarded by LWT. Several elements of programming from both parent stations held over to Thames, but everything else was ABC.

The new company turned out to be a worthy successor to both its parents, despite machinations in the boardroom. A couple of years after its formation, ABPC was taken over by EMI, requiring assurances to the regulator that Thames would be managed separately from ATV, in which EMI also had a stake. Thames made plenty of money, but its parents seemed less interested in developing the broadcaster, instead using its resources to fund other ventures. Yet the company held its own. In 1985, Carlton Communications made a bid for Thames, having obtained agreement from EMI and BET to sell their shares, and having understood that the takeover would not be blocked by the regulator. However, key members of Thames management opposed the move and appealed to the Independent Broadcasting Authority (as it now was). The IBA's compromise proposal, that Carlton take 49% of the company, was not of interest, and the deal collapsed. Carlton tried again in 1991, just before the upcoming franchise round, but again failed. BET sold out to EMI.

Success finally came Carlton's way in 1992, when it opposed Thames in the 'new rules' post-1990 Broadcasting Act franchise round - and won, primarily by offering £42 million to Thames's £33m. Another consortium, involving Virgin and, once again, David Frost, bid high but failed on quality grounds.

It is widely believed in TV history circles that a contributory factor in the demise of Thames was Margaret Thatcher's dislike of the station in the wake of the Death on the Rock documentary (tx. 28/4/1988), part of the This Week series (inherited from Rediffusion and broadcast 1956-92). The programme investigated the killing of three IRA members in Gibraltar by the SAS the previous month, concluding that what actually happened was an execution: no attempt had been made to arrest the men and the reasons given for failing to do so did not hold water. Foreign Secretary Geoffrey Howe attempted to stop the broadcast by writing to the IBA chairman, Lord Thomson, who refused to intervene in the interests of free speech. The right-wing press weighed in with heavy criticism of the broadcast after the event, and eventually an independent enquiry, headed by former television management executive and government minister Lord Windlesham, was held. The enquiry delved deep into the TV documentary-making process and essentially exonerated Thames, although it found some errors had been made.

Mrs Thatcher was allegedly extremely displeased with Thames, but whether she, as a result, put pressure on the IBA to choose someone else or whether, as is perhaps more likely, Thames suffered more from a lacklustre primary shareholder and rather too small a bid in what is widely regarded as little more than an auction will probably never be known. Thames Television left the air as a broadcaster on 31 December 1992, effectively ending a television tradition traceable back to the launch of ITV on 22 September 1955.

For over twenty years, Thames served the capital and the network with a long-running, broad-based and extensive series of programmes, several of which either continue or are well-remembered today - so extensive, in fact, that in 1977 the company was able to buy a full week of programming on WWOR-TV in New York and run only its own shows.

Well known for comedy, light entertainment, and drama series, Thames lured Benny Hill from the BBC in 1969 for a new version of The Benny Hill Show, featuring the comedian's trademark lecherous on-screen persona, double-entendres and sight-gags. The series ran until 1989, and sold to 104 countries. Another highlight was the early sitcom Bless This House (1971-76), starring Sid James, set in Putney and highlighting the generation gap.

In a slightly more serious vein was John Mortimer QC's Rumpole of the Bailey (1978-79; 1983; 1987-88; 1991-92), starring Leo McKern, while race-based sitcom Love Thy Neighbour (1972-76) was less restrained than, and as controversial as the BBC's Till Death Us Do Part (1966-75) and, in its day, almost as successful.

The early 1970s also saw the establishment of a film production subsidiary, Euston Films, which was responsible for some of the most impressive of ITV's network offerings, including a successor to the BBC's Nigel KnealeQuatermass dramas (1979), made on 35mm film with high production values and a budget of £1 million. Broadcast of the series was held up by a strike that took ITV off the air for over two months.

Euston also produced the high-octane police drama The Sweeney (1975-78), starring the late John Thaw and Dennis Waterman as Flying Squad ('Sweeney Todd' in Cockney rhyming slang) officers, which generated two spin-off feature films. Similarly successful was Minder (1979-84), produced by Verity Lambert, also starring Dennis Waterman, this time as a bodyguard for shady London underworld character Arthur Daley, played by George Cole.

Thames's The Naked Civil Servant, broadcast on 17 December 1975, was a 90-minute drama written by Granada refugee Philip Mackie, with a startling, multiple award-winning performance by John Hurt as Quentin Crisp.

Thames made its mark in children's television, with series ranging from the memorable Tomorrow People (1973-79) to Magpie (1968-80) - conceived as Thames's answer to Blue Peter, but rapidly establishing an identity of its own - and Rainbow (1972-95). Among Thames's successful non-fiction programming were talent show Opportunity Knocks (1964-78), inherited from Rediffusion, and the very popular This is Your Life (1969-94).

In addition to the enduring This Week, Thames's documentary output included The World At War (1973-74), an exhaustive 26-part history of the Second World War, its origins, progress and legacy, produced by Jeremy Isaacs and narrated by Sir Laurence Olivier - another example of Thames's ability to satisfy audiences at home and abroad.

After losing its franchise, Thames continued as an independent production company, and was bought by Pearson Television. In 2003 Thames came together with Talkback to form TalkbackThames as the UK production arm of Fremantle Media, part of RTL. Today TalkbackThames produces such programmes as police drama The Bill (ITV, 1984-), Property Ladder (Channel 4, 2001-) and Pop Idol (ITV, 2001-2003). The phenomenally successful The Bill celebrated its 20th anniversary with a live show; another live broadcast marked ITV's 50th anniversary on 22 September 2005.